Gather all the ingredients before starting the recipe.

• Melt 1 tbsp unsalted butter in a small skillet over medium heat. Add 1/2 thinly sliced sweet onion and 10 whole pearl onions, thawed. Season with kosher salt and freshly ground black pepper and sauté until the onions are tender, about 6 minutes. Add 2-3 handlfuls frozen peas and cook for 4-5 minutes, stirring occasionally, until the peas are heated through. Taste and adjust seasoning before serving.